Delay-action



No Model.) v

E. L. ZALINSKI 8c H. J. SMITH.

DELAY ACTION PRIMER.

No. 405.647. PatentedJune 18,l 1889.

siii

STnTns PATENT Tries.

EDMUND L. ZALINSKI, OF THE UNITED STATES ARMY, AND HENRY JULIUS SMITH, OF POMPTON, NEW JERSEY.

DELAY-ACTEON PRHWER.

SPECIFICATION forming part of Letters Patent No. 405,647, dated June 18, 1889.

I Application filed November 23, 1888. Serial No. 291,679. (No model.)

- vented certain new and useful Improvements in Delay-Action Primers, of which the following is `a specification, reference being had therein to the accompanying drawings.

This invention relates to electric fuses of the kind used in mining, blasting, &c.

Theinvention consists in the construction and interposition ofV a delay-action piece between the ignitor or primer and the detonator.

In blasting and mining operations, especially in tunnels and shafts, it is frequent-ly desirable to place a large number of blastingcharges in proximity, so that a central group can be red, breaking up or loosening a central core by a shot or blast, and then by a Succeeding shot of a group near or surrounding this core the rock or ore is thrown toward or into the space thus created. This is usually done at two operations; but suoli a series l of steps is inconvenient and often dangerous. It will be apparent that the first explosion will be likely to break the delicate electrical connections if all the blasts are charged. Hence it is not expedient, if not impossible, to ire one set of bla sting-charges (as of the core) by one battery-impulse and another or second set by another impulse. It is very desirable to ignite all the charges at once, but cause them to explode in succession. lVith this object in view We provide a delay-action fuse between the primers or ignitors and the detonators of some or all the blasts of a group, by the use of which all the charges may be ignited simultaneously, but the explosions will take place successively.

Referring now to the drawings, Figure l illustrates a section of a delay-action or time primer or fuse in its relation to the ignitor and detonator, the delay-action piece being made detachable. Fig. 2 is a sectional View of a similar fuse connected to the detonator. Fig. 3 is a section similar to Fig. 2 with the ignitor omitted. Fig. 4 is a section of the delay-action fuse made integral with the ignitor, and Fig. 5 is a section of a delay-action fuse with metallic casing. v

The letters a afindicate the conducting- Wires, which are insulated in usual manner, as by textile covering b. The ends of the wires are connected by a platinum bridge or similar bit of wire, which becomes heated by the passage of electricity in the usual manner. Surrounding or in proximity to this bridge there is a small igniting-charge c-say of fulminate of mercury. closed in a casing of plastic or'other material, as indicated by the letter A, Figs. 1 and 2.

B indicates a plug or piece lof Wood, paperpulp, plaster, or other material, having a passage d, which leads from the seat efor the primer to the end of the plug. The passage d is lled with mealed powder or other slowburning composition in such quantity as is desirable to burn for the desired interval of time, usually but a fraction of a second. The passage d may have vent-apertres g, which are filled with wax, tallow, or similar material, and by preference the entire block B is covered with a coat of such waterproofing material as can be readily done by dipping.

The modification shown in Figs. 2 and 3 is such a structure as results from taking the lower end B of the plug B and inserting it permanently' in the casing of the det-onator D, leaving a space above the same to contain the ignitor.

In Fig. 4 the passage d is in the sulphur or other piece A', which forms t-he inclosing-casing A, the passage d having one end in close proximity to the igniting-charge at c.

In Fig. 5 A2 indicates a delay-action fusepiece in a metallic ycasing instead of the plug B, this casing being ready Ato receive the ignitor at one end and convey the fire therefrom to the detonator.

The lower end of the passage d, Figs. 2, 3, and 4, and the top of the slow-burnin g charge in the passage D should be protected by a coating of varnish, wax, rubber, or other Waterproofing and inclosing material, as at h 71., and the entire piece l5 may be covered with such material by dipping in the varnish or Wax. The Wax will serve to retain the This may be in- TOO moisture.

ignitor, delay-charge holder, and detonator.

together, and will surely seal lall joints against It will at once 4appear that the construction' 'of this delay-action charge-holder may vary, the generic idea being that a delay-action A.charge shallbe interposed between the ignitfing anddetonatingcharges, and the species holder is'` separable from the detonator andA .considered most important, herein described, is that y'in which the delay-action charge- 'capable of separate shipment and use.

It will be readily lunderstood that such .charge-holders may be made to contain such a quantity oflslowburning powder as will seeurethevnece'ssary interval between the igniv tion and. explosion, be the same more or less.

The commercial detonator is usually a metallic tube' open' at. one end and closedl at the other and 'containing ten to thirty grains of fulminateof mercury near the closed end. .Such de tonators4 are lprocurable in most min ing regions and are well known vtoI the trade. v hat We claim isf- 5 1. The combination,'w1 th an electric ignitor anda detonator of the character described, of Ian interposed '.delayaction primer or timefuse, substantially as described.

25A' delay-action primer consisting of a' 39/ charge-holder chambered to receive an electrical ignitor and shaped it a commercial ydetonator `andhagving a slow-burning or time charge contained in'said holder, substantially as stated. f

3. A' delay-action pri-mer consisting of a charge-holder having vents,- a time-charge contained in said holder, a chamber to receive an electrical ignitor in proximity tosaid charge, and being shaped to it the commer- 'cialdetonatoig substantially as described 4. The combination, with the charge-holder of a shape to tit the detonator and having a chamber for the ignitor, of a ,time-charge contained iny saidholder with a Water-proof coating covering said burning' charge.

5. The combination, With an electric ignltor -and aA detonator, 0f a separate delay-action charge-holder shaped to connect both';

6. The delay-action charge-holder described chambered to receive the igitor, shaped to t the commercial detonator, and covered ywith a coating of Water-proof material, sub- 

